The present invention relates to a device for adjusting the position of the post-accelerator inside an agricultural harvesting machine, in particular inside a forage harvester.
Due to the trend toward developing increasingly more powerful forage harvesters with wider front harvesting attachments, the performance requirements on the post-accelerator have also increased. In addition, different weather conditions, throughput masses and types affect the quality and reliability of the conveyance of crop material inside the harvesting machine. For example, when grass is drawn into the machine under moist conditions, and when the mass of conveyed material differs, clumps may form, which greatly impair the flow of crop material and, in the extreme case, may result in blockage. These problems affect conveyance inside the harvesting machine and during ejection.
Publication DE 19732722 describes a post-accelerator in the form of a conveying fan for a forage harvester. It should be possible to clean out this conveying fan quickly if blockages occur. A wearing plate is installed for this purpose in the feed chute on the frame part, in the direct vicinity of the conveying fan. Both of the devices are removable, thereby making it possible to access the interior of the fan and remove the blockage. In addition, the devices are designed such that the distance between them may be varied, thereby enabling the gap between them and the rotational circle of the conveying rotor to be changed manually.
The disadvantage of the embodiment disclosed in DE 19732722 is that the amount of intervention time is considerable, since intervention must be performed manually. Under these conditions, it is not economical to respond spontaneously to changes in crop material flow, and this response may not be carried out immediately without interrupting the harvesting operation. In addition, the various adjusting screws must be installed exactly, since even a slight deviation of a single adjusting screw results in uneven conditions on the inside of the rotational housing. As a result, moist crop material—in particular—becomes stuck, which may lead to increased build-up and disruption of crop material flow. This section must therefore be monitored on a regular basis. This also applies for the density of the crop material. In all, it is not possible according to the invention disclosed in DE 19732722 to respond to changes in the flow of crop material without disrupting field work. In addition, the response must be carried out manually, which results in considerable down time and assembly work. If the cleaning and assembly work is not carried out, crop material is lost, since the poorer flow of crop material prevents an optimal stream of ejected crop material into a hauling vehicle. Depending on the weather conditions and the effects of wind, this can result in up to 30% loss in crop material.
In addition, publication DE 102 31 316 A1 discloses a post-accelerator of a forage harvester that is adjustable using an axle-displacing mechanism. The axle-displacing mechanism, which is supported in a support frame fixedly located on the machine housing, acts on at least one side of the axle of the post-accelerator. To guide the post-accelerator, the post-accelerator includes integrated sliding blocks, which may slide back and forth on the guide surfaces located parallel with each other on the support frame. The post-accelerator is displaced using four guide axles, which are integrated—in pairs—in the axle-displacing mechanism. The guide axles are fixed in position with one end on the particular sliding block, thereby enabling the fixing in position of the post-accelerator to be coupled with the axle-displacing mechanism.
The disadvantage of this embodiment is that, if the axle-displacing mechanism fails or has been removed, it is no longer ensured that the post-accelerator is fixed in position to an adequate extent, and the problem must be eliminated before the harvesting process may continue.